Attacked with 6 Shards? How? Where? Why? The minimum is 12! (So I guess he used the double Drizzle perk).
However, yes, I agree, both attacker and defender should lose Slothsards, which I thought was already added, but we'll fix for next round!
And yes, shield should also be lost, however I'm assuming with the 'failed' attack, it never hit the metric to use the shield, so yes, both need fixed.